<template>
    MyLeft组件
    <div>
        count: {{ count }}
        <button @click="count++">+1</button>
    </div>
</template>

<script setup>
import { ref,onUnmounted, onMounted,onActivated,onDeactivated } from 'vue';
const count =ref(0)

onMounted(()=>{
    console.log('MyLeft组件被挂载了')
})
onUnmounted(()=>{
    console.log('MyLeft组件被挂载了')
})
onActivated(()=>{
    console.log('MyLeft组件被激活了')
})
onDeactivated(()=>{
    console.log('MyLeft组件被缓存了')
})
</script>